Solenoid operated limit switch assembly



Jan. 12, 1965 A. R. CHASAR EIAL 3,165,600

SOLENOID OPERATED LIMIT SWITCH ASSEMBLY Filed Feb. 23. 1961 2 Sheets-Sheet l INVENTORJ. fl/vrwwvr R. Cmrwm flu-"a/m'a viz/7011mm Z I @m' QMJM arrmwzns' Jan. 12, 1965 A. R. CHASAR ETAL 3,165,600

souzuom OPERATED LIMIT swncn ASSEMBLY Filed Feb. 23, 1961 2 Sheets-Sheet 2 ANV TORJ. lilvrwozvr Mrs-an Hub/v.50 w lk'manaar YTTORNEYJ United States Patent 3 165 600 soLENorn OPERATED Llivili swrren ASEMBLY Anthony B. Chasar and Alfonso W. Mehrhrodt, Cleveland, Ohio, assignors to The Tries Company, Cleveland, Ohio, a corporation of Ohio Filed Feb. 23, 1961, Ser. No. 91,020 7 Qlairns. (Cl. ass-47 This invention relates to improvements in a switch assembly and more particularly to a solenoid operated limit switch assembly. a

An object of the present invention is to provide a limit switch assembly having an actuator arm movable endwise between inoperatable and operatable positions with the switch adapted to be actuated in the operatable position.

A further object of the present invention is to provide a limit switch assembly characterized by its inexpensive manufacturing cost, structural simplicity, ease of assembly of its component parts, strong and sturdy nature, low operating cost, operating efficiency, adaptability to use any conventional limit switch, long and accurate switch wear life, etc.

Other features of this invention reside in the arrangement and design of the parts for carrying out their appropriate functions.

Other objects and advantages of this invention will be apparent from the accompanying drawings and description and the essential features will be set forth in the appended claims. s

In the drawings,

FIG. 1 is a side elevational view of the limit switch assembly disclosed herein mounted on a supporting frame with the actuator arm thereof shown horizontally in solid lines in inoperatable (retracted) and unactuated position and in dot-dash lines in operatable (advanced) and unactuated position before movement in the actuating direction to the switch actuated positions shown extending diagonally downwardly toward the left in dotted lines;

FIG. 2 is a horizontal sectional view taken generally along the line 2-2 in FIG. 1;

FIG. 3 is a horizontal sectional view taken generally along the line 3-3 in FIG. 1 through the pivot shaft of the switch;

FIG. 4 is a vertical sectional view taken generally along the line 4-4 in FIG. 3;

FIG. 5 is a schematic illustration of the interior construction of a conventional limit switch adapted to be used in this assembly;

FIG. 6 is a side elevational view of a second form of limit switch assembly with generally the same actuator arm positions shown as in FIG. 1; while FIG. 7 is a bottom view of the assembly in FIG. 6 taken generally along the line '77 in FIG. 6.

Before the construction here illustrated is specifically described, it is to be understood that the invention here involved is not limited to the structural details or arrangement of parts here shown since a construction embodying the present invention may take various forms. It also is to be under-stood that the phraseology or terminology herein employed is for purposes of description and not of limitation since the scope of the present invention is denoted by the appended claims.

Those familiar with this art will recognize that this invention may be applied in many ways. One suitable application is to use this limit switch assembly 1% in place of the limit switch assembly having limit switch LS8R in FIGS. 9A and 23 in the copending United tates patent application, Serial No. 66,776; entitled Mechanical Load Handling, Transfer and Storage Equipment; and filed November 2, 1960, by Anthony filbihhfi Patented Jan. 12, 1965 R. Chasar, an inventor herein. The operation described herein will be generally the same as in this aforesaid copending application.

Limit switch assembly 1% in FIGS. l4 includes switch unit 12, actuator arm 2!), and connection or connecting means 22 operatively connecting unit 12 and arm 2%). Switch unit 12 has a mounting face 12a and encases any suitable limit switch construction. Such switch unit 12 is shown schematically in FIG. 5 as including by way of example actuable stationary contacts 13, 13, 14 and 14; and movable contacts 15a and 15b located respectively at upper and lower ends of movable contact plate 15 rigidly carried by arm 19. Arms 19 and 20 are rigidly secured to pivot shaft 24 of connection 22 so that movement of actuator arm 20 by force F from the solid line position to the dotted line position will cause shaft 24, rotatably mounted in the housing of switch unit 12,

to move counterclockwise about axis A against the force of spring 18 to move contact plate 15 to the dotted line position to close stationary contacts 14, 14' by movable contacts 15a and 1515' while opening normally closed contacts 13, 13. Upon release of actuating force F on arm 2% spring 18 will return the parts to the solid line position; open contacts 14, 14; and close contacts 13, 13. Actuator arm Ztl includes link 26 having rotatably secured to its distal end a switch actuating, trip engaging roller 28 by pivot pin 29; This limit switch is thusv moved from the untripped or unactu-ated position P1 to the tripped or actuated position P2 by pivotal movement of arm 2% in actuating dierction D1. i

This structure thus far described applies generally to any conventional limit switch, and it should be readily apparent that any satisfactory or conventional limit switch construction may be used within switch unit 12 to be actuated by oscillation of pivot shaft 24 herein because the schematic construction in FIG. 5 is shown only for purposes of illustration. One suitable form of construction of said switch unit 12 is shown in United tates Patent No. 2,352,815, issued July 4, 1944, to H. L. Van Valkenburg, and entitled Electric Switch.

Limit switch assembly 1% herein is disclosed as being mounted and operable in generally the same manner as the limit assembly, including limit switch LS-8R, in FIG. 9A of the copending application. As in this copending application, frame 32 is adapted to be driven in a vertical direction D2 by a suitable motor (not shown) by'a circuit through closed contacts 13 in switch unit 12 connected to this supporting frame 32. A stationary frame has located at spaced apart locations along direction D2 a pair. of horizontally aligned stationary frame arms 35 at each location with each arm pair having atrip surface 3ST. Frame 32 carries a load vertically in trip surface 3ST; and after actuator arm 24? moves to the actuated position P2, suitable mechanism on frame 32 transfers the load onto the shelf provided by the pair of frame arms 35 corresponding to this trip surface 3ST. As frame 32 moves in direction D2, roller 28 engages trip surface 3ST to move the switch components from unactuated position P1 in actuating direction D1 to actuated position P2 in FIGS. 1 and 5 because connection 22 includes a pivot element, comprising pivot shaft 24, pivotally connecting actuator arm 29 to switch unit 12 for arcuate actuating movement of arm 20 in direction D1 about pivot axis A when roller 28 of arm'Ztl engages with trip 3ST during movement of frame 32 in direction D2 relative to trip 3ST. Movement in actuating direction D1 causes switch contacts 13 to open and contacts 14 to be closed by contact plate 15 in the dotted line position in FIG. 5 upon switch actuation.

Switch unit 12 is connected to supporting frame 32 by securing means comprising two nut and bolt units 3 33, extending through holes in the housing of switch unit 12 and located at diagonally opposite corners, for securing it onto mounting frame 32.

In the aforesaid copending application, there are a plurality of vertically spaced apart pairs of frame arms 35, and frame 32 is adapted to stop in horizontal alignment with any selected one of these pairs of arms 35 upon movement of actuator arm from unactuated position P1 to actuated positionPE. However, during travel in vertical direction D2, it is desirable to keep actuator arm 2% in inoperatable or retracted position P4 during travel past unselected arms and then advance arm 20 to operatable or advanced position P3 immediately before arriving at the preselected arms 35 with which frame 32 is to be stopped in horizontal alignment. This advancing action is provided by the power means mentioned hereinafter having solenoid 62 electrically energized. This electrical energization may be caused in any suitable manner, such as by manually closing an energizing circuit at the appropriate time or by a counter mechanism counting vertically spaced arms 35 or the distance traveled by frame 32 in direction D2, as disclosed .in said copending application.

This power means is provided for moving arm 20 relative to frame 32 in direction D4 (non-parallel to actuating direction D1) between inoperatable or retracted position P4 with arm 26 located. to be out of actuating alignment with trip 3ST during travel of frame 32 in direction D2 and an operatable or advanced position P3 with arm 20 located to be in actuating vertical alignment with trip 3ST. This power means takes the form of an electrically energizable solenoid 62 for moving arm 26 in direction D4 from position P4- to position P3 upon energization of the solenoid by its lead wires 62a and helical spring 64, or other suitable resilient means, for moving arm 26 in opposite direction D5 from position P3 to position P4 upon de-energization of solenoid 62. Solenoid 62 includes a conventional coil member 62b having telescoped therein relatively movable armature member 62c movable in direction D4- upon energization of coil 62b.

The power means moves arm 21) relative to switch unit 12 and pivot element in direction D4 or D5 between positions P3 and P4. Solenoid 62 and spring 64 is constructed so that each operatively connects arm 20 and pivot element 45 of switch unit 12. Connection 22 may take any suitable form and includes hereinpivot element 45 pivotally connecting actuator arm 20 to switch unit. 12.

As will be apparent hereinafter, and by consideration of the drawings, the description of the structure and mode of operation in the preceding paragraphs also applies generically to the same named or numbered parts, positions, directions and movements in FIGS. 6 and 7.

Pivot element 45 includes pivot shaft 24 extending from switch unit 12; bracket 47 secured to shaft 24 against rotation by clamp screw and nut unit 48; parallel guide grooves 49 in bracket 47 to slidably receive parallel portions 26a of link 26 of arm 26 for movement generally perpendicular to pivot axis A, in direction D4 or D5, and endwise of arm 29; and solenoid mounting plate 52 secured by mounting screws 50 and 51 extending respectively through holes in bracket 47 and plate 52 and in plate 52 to be screwed into threaded holes in frame housing 62d of solenoid 62 in FIG. 3. Solenoid 62 has armature member 62c secured at its outer end to links 26 of arm 20 by one end of link extending into slot 620' cut in the end of armature 62c and secured therein by pin 61 extending through aligned holes in link 7i? and armature 62c and has its other end straddling slit tubing 72, preferably of nylon to resiliently cushion the operation, sprung over vertically extending connecting portion 260 joining vertically spaced apart and horizontally extending link portions 26a of link 26. Spring 64 has its opposite ends secured to mounting screw 51 on bracket 47 and through a hole 26 in link 26 of arm d1. 20 with spring 64 located generally coplanar with link 26 of arm 26.

In FIGS. 6 and 7, limit switch assembly 114) is shown. Connection or connecting means 122 may take any suitable form and includes herein pivot element pivotally connecting actuator arm 29 to switch unit 12. Pivot element 145 includes pivot shaft 24 extending from switch unit 12; bracket 147 secured to shaft 24 against rotation by clamp screw and nut unit 48; parallel guide grooves 149 in bracket 147 to slidably receive link 26 of arm 29 for movement generally perpendicular to pivot axis A, in direction D4 or D5, and endwise of arm 21 and mounting screws 150 and 151 extending through holes in bracket 147 and screwed into threaded holes in frame housing 62d of solenoid 62 in FIG. 7. Solenoid 62 has armature member 620 secured at its outer end to link 26 of arm 20 by one end of link extending into slot 62c cut in the end of armature 62c and secured therein by pin 61 extending through aligned holes in link 170 and armature 62c and has its other end secured to link 26 by screw 131 extending through an aligned hole in link 17% and slot 26d (see FIGS. 3 and 4) in link 26, formed by link portions 26:! and 260. Screw 181 is secured to link 26 against endwise movement by assembled square washer 182, nut 183 and lock washer 184. Spring 164 is a helical spring telescoped over armature member 620 between coil member 62b and washer 1S5 telescoped over link 1741* and abutted against the end of armature 620.

The construction in FIGS. 6 and 7 has the advantages of eliminating solenoid mounting plate 52 in FIG. 3, conveniently locating spring 164, and providing maximum horizontal bearing length for link 26 in guide grooves 149 in FIG. 7.

It should be noted that when the parts in FIGS. 14 and 67 are in their operatable or advanced position PS, the components of the power means are so located to minimize the retarding inertia caused by their weight during arcuate movement of arm 20 about axis A in actuating direction D1 during switch actuation from position P1 to position P2. Solenoid 62 and spring 64 or 164 are connected to move with and to have the same arcuate actuating movement in direction D1 about axis A as arm 20 and are carried near pivot axis A to minimize the retarding inertia.

The advantages of the constructions in FIGS. 1-4 and 67 are many, and especially when used in the circuit disclosed in the aforesaid copending application. First, a conventional limit switch, having arm 20 secured against endwise movement to bracket 47 by lock plate 52 secured to bracket 47 by screw 50, can be easily converted to the design in FIGS. 14 by merely adding solenoid 62 having armature slot 630', spring 64, link 70, pin 71, slit tubing 72, screw 51, and by deepening guide grooves 49 to give the sliding action of arm 23 in directions D4 and D5. Second, longer and more accurate wear life is obtained by switch unit 12 because arm 20 is normally in position P4 so does not have to be overworked by engagement and actuation by every trip surface 3ST but is only extended to operatable position P3 at the preselected trip 3ST to be actuated only once where desired. Third, no holding contacts are required in the operating circuit in parallel with contacts 13, 13 to maintain energized the driving motor of frame 32 as switch unit 12 is actuated by each trip 3ST before the selected stopping position is reached. Fourth, one can select, either manually or by suitable counting mechanism, the time to advance arm 21 from position P4 to position P3 for actuation in direction D1 from position P1 to position P2 at the desired trip surface 3ST so that undesired trips 3ST may be passed during movement of frame 32 in direction D2 without switch actuation. Fifth, this limit switch assembly 16 or 1141 may be used for many different purposes in addition to that disclosed in the aforesaid copending application, such as on hoisting devices, conveyors, counting devices, sorting devices, etc. Sixth, frame 32 can be caused to cont nue movement in direction D2 after being stopped in position P2 in a very simple manner by this construction. Dre-energizing solenoid 62b will cause spring 64 or 164 to move arm 26 from position P2 to position P4 to close contacts 13 and permit travel or" frame 32 in direction D2 in the same manner as earlier described. Sixth, swinging arm 29 in actuating direction D1 is easily done with minimum force because of the low inertia construction previously mentioned as resulting from the structural location of solenoid 62 close to axis A.

Various changes in details and arrangement of parts may be made by one skilled in the without departing from either the spirit of this invention or the scope of the appended claims.

What is claimed is:

1. A switch assembly comprising a switch unit having actuatable contacts and adapted to be connected to a supporting frame, an actuator arm, connecting means movably connecting said arm to said switch unit with said arm engageable with a trip havingrelative movement with respect to said frame for actuating said contacts of said switch unit by causing arm movement relative to said switch unit in a switch actuating direction, power means for moving said arm relative to said switch unit in a direction non-parallel to said actuating direction between an inoperatable position with said arm located to be out of actuating alignment with said trip and an operatable position with said arm located to be in actuating alignment with said trip, said connecting means including a pivot element pivotally connecting said arm to said switch unit for arcuate actuating movement of said arm about a pivot axis in said actuating direction, said power means connected to have the same arcuate actuating movement as said arm and being carried by said assembly near said pivot axis to minimize retarding inertia during arcuate movement.

2. A switch assembly, as set forth in claim 1, with connecting means including a guide on said pivot element for said arm to slide on said pivot element generally perpendicular to said pivot axis and endwise of said arm between said positions, said power means including an electrically energizable solenoid having a relatively movable coil member and armature member with one of said members carried by said pivot element and the other of said members carried by said arm so that energizing said coil member moves said arm in said one direc tion between said positions.

3. A switch assembly, as set forth in claim 2, with a spring located generally coplanar with said arm and operatively connecting said arm and pivot element for moving said arm in the opposite of said one direction between said positions.

4. A switch assembly, as set forth in claim 2, with a helical spring telescoped over said armature member between said arm and coil member and operatively connecting said arm and pivot element for moving said arm in the opposite of said one directions between said positions.

5. A switch adapted to be mounted to a supporting frame and actuatable by a relatively moving trip, said switch having a shaft pivotable to actuate said switch, a solenoid coil mounted on said shaft with its axis disposed substantially at right angles to said shaft, an elongated operative member longitudinally slidably mounted relative to said solenoid coil for movement generally parallel with the axis of said coil, said operative member responsive to energization of said coil in such manner as to move from a position out of actuating alignment with the trip to a position in alignment with said trip whereby a portion of said operative member engages said trip to pivot said shaft and actuate said switch.

6. A switch as set forth in claim 5 including resilient means automatically returning said operative member from said second mentioned position to said first mentioned position when said coil is de-energized.

7. A switch adapted to be mounted to a supporting frame and actuatable by a relatively moving trip, said switch having a shaft pivotable to actuate said switch, a solenoid coil, a connector fixedly mounting said coil to said shaft with the axis of said coil disposed perpendicuiar to the axis of said shaft, an elongated armature member longitudinally slidablymounted in said coil, said connector having means providing guides grooves disposed parallel with and laterally offset from said armature, an elongated actuator arm slida'bly mounted in said guide grooves and projecting outwardly beyond either side of said connector, a link connecting one end of said armature to one end of said arm, said coil encrgizable to cause said armature and said arm to move longitudinally from a retracted position to one wherein the free end of said arm projects outwardly into the path of a relatively moving trip to be struck thereby and cause pivoting of said shaft and actuation of said switch, and spring means biasing said arm and said armature toward said retracted position out of the path of a relatively moving trip.

References Cited in the file of this patent UNITED STATES PATENTS 1,531,428 Way Mar. 31, 1925 1,913,735 Thompson lune 13, 1933 2,499,979 Smith Mar. 7, 1950 2,656,109 Lindars Oct. 20, 1953 2,767,269 Kerr Oct. 16, 1957 

1. A SWITCH ASSEMBLY COMPRISING A SWITCH UNIT HAVING ACTUATABLE CONTACTS AND ADAPTED TO BE CONNECTED TO A SUPPORTING FRAME, AN ACTUATOR ARM, CONNECTING MEANS MOVABLY CONNECTING SAID ARM TO SAID SWITCH UNIT WITH SAID ARM ENGAGEABLE WITH A TRIP HAVING RELATIVE MOVEMENT WITH RESPECT TO SAID FRAME FOR ACTUATING SAID CONTACTS OF SAID SWITCH UNIT BY CAUSING ARM MOVEMENT RELATIVE TO SAID SWITCH UNIT IN A SWITCH ACTUATING DIRECTION, POWER MEANS FOR MOVING SAID ARM RELATIVE TO SAID SWITCH UNIT IN A DIRECTION NON-PARALLEL TO SAID ACTUATING DIRECTION BETWEEN AN INOPERATABLE POSITION WITH SAID ARM LOCATED TO BE OUT OF ACTUATING ALIGNMENT WITH SAID TRIP AND AN OPERATABLE POSITION WITH SAID ARM LOCATED TO BE IN ACTUATING ALIGNMENT WITH SAID TRIP, SAID CONNECTING MEANS INCLUDING A PIVOT ELEMENT PIVOTALLY CONNECTING SAID ARM TO SAID SWITCH UNIT FOR ACTUATE ACTUATING MOVEMENT OF SAID ARM ABOUT A PIVOT AXIS IN SAID ACTUATING DIRECTION, SAID POWER MEANS CONNECTED TO HAVE THE SAME ARCUATE ACTUATING MOVEMENT AS SAID ARM AND BEING CARRIED SAID ASSEMBLY NEAR SAID PIVOT AXIS TO MINIMIZE RETARDING INERTIA DURING ARCUATE MOVEMENT. 